When composing myexperience with the injured filly, I knew people were going to worry about the sand and just forgot to add this note…and thanks to barrelracer612 for her concern…We live in the desert and sand is our ground. Miles wide and many feet deep. Our horses, especially the mustangs who were born in the wild, have fared pretty well. We lost 2 horses in 10 years from colic but surprisingly, neither from sand! We have deep metal feeders and never intentionally feed off the ground,of course none of the horses leave it all in there. We feed a dose of bran once a week but would be interested in any other or better preventative measures.